Astrophysical Bulletin最新文献

{"title":"Galaxies at (boldsymbol{zgtrsim 10}) and New Opportunities for Testing Cosmological Models","authors":"S. V. Pilipenko,&nbsp;S. A. Drozdov,&nbsp;M. V. Tkachev,&nbsp;A. G. Doroshkevich","doi":"10.1134/S1990341324600844","DOIUrl":"10.1134/S1990341324600844","url":null,"abstract":"<p>The initial power spectrum of density perturbations, generated during the inflationary epoch, is now constrained by observations on scales of <span>(lambda&gt;5)</span> Mpc and has a power-law form. The peculiarities of the inflationary process can lead to the appearance of non-power-law contributions to this spectrum, such as peaks. The exact size and shape of the peak cannot be predicted in advance. In this paper, we propose methods for searching for such peaks in the region of the spectrum with <span>(lambda&lt;5)</span> Mpc. Perturbations on these scales enter the nonlinear stage at <span>(zgtrsim 10)</span>, which is now becoming accessible to observations. Our studies of numerical models of the large-scale structure with peaks in the initial spectrum have shown that spectral features on scales of <span>(lambda&gt;0.1)</span> Mpc manifest in the clustering of galaxies, as well as affect their mass function, sizes, and density. Studying these characteristics of distant galaxies will allow us to constrain cosmological models with peaks.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"79 4","pages":"535 - 547"},"PeriodicalIF":1.3,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring of DDO 68 ‘‘Northern Ring’’ SF Regions in 2016–2023","authors":"S. A. Pustilnik,&nbsp;Y. A. Perepelitsyna,&nbsp;A. S. Vinokurov,&nbsp;E. S. Egorova,&nbsp;A. S. Moskvitin,&nbsp;V. P. Goranskij,&nbsp;A. N. Burenkov,&nbsp;O. A. Maslennikova,&nbsp;O. I. Spiridonova","doi":"10.1134/S1990341324600881","DOIUrl":"10.1134/S1990341324600881","url":null,"abstract":"<p>DDO 68 is a star-forming (SF) dwarf galaxy residing in a nearby void. Its gas metallicity is among the lowest known in the local Universe, with the <span>(12+log(textrm{O/H}))</span> parameter in the range of 6.96–7.3 dex. Six of its SF regions are located in or near the so-called ‘‘Northern Ring’’, in which the Hubble Space Telescope (HST) images reveal many luminous young stars. We present for these SF regions (Knots) the results of optical monitoring in 35 epochs during the years 2016–2023. The data was acquired with the 6-m (BTA) and 1-m telescopes of the Special Astrophysical Observatory, and the 2.5-m telescope of the MSU Caucasian Mountain Observatory. We complement the above results with the archival data from 10 other telescopes for 11 epochs during the years 1988–2013 and with three our BTA observations between 2005 and 2015. Our goal is to search for variability of these Knots and to relate it to the probable light variations of their brightest stars. One of them, DDO 68-V1 (in Knot 3), was identified in 2008 with a luminous blue variable (LBV) star born in the lowest metallicity environments. For Knot 3, variations of its integrated light in the previous epochs reached about <span>(0overset{textrm{m}}{.}8)</span>. In the period since 2016, the amplitude of the variations in Knot 3 has reached about <span>(0overset{textrm{m}}{.}3)</span>. For the rest of the Knots, due to the lower amplitudes, the manifestation of variability is less pronounced. We examine the presence of variability via the <span>(chi^{2})</span> criterion and the Robust Median Statistics and discuss the robustness of the detected variations. The variability is detected according to both criteria in the light curves of all Knots with the <span>(chi^{2})</span> confidence level at <span>(alpha=0.0005)</span>. The peak-to-peak amplitudes of the variations are approximately <span>(0overset{textrm{m}}{.}09)</span>, <span>(0overset{textrm{m}}{.}13)</span>, <span>(0overset{textrm{m}}{.}11)</span>, <span>(0overset{textrm{m}}{.}08)</span>, and <span>(0overset{textrm{m}}{.}16)</span> for Knots 1, 2, 4, 5, and 6, respectively. The amplitudes of the related variations of the brightest supergiants in these regions can reach about <span>(3overset{textrm{m}}{.}0)</span>.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"79 4","pages":"594 - 613"},"PeriodicalIF":1.3,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of Gravitational Waves GW150914 and GW170104 as a Black Hole Merger","authors":"G. Mathew,&nbsp;P. G. Louie Frobel","doi":"10.1134/S1990341324600042","DOIUrl":"10.1134/S1990341324600042","url":null,"abstract":"<p>Gravitational waves are ‘‘ripples’’ in space-time caused by some of the most violent and energetic processes in the Universe. A study of gravitational waves GW150914 and GW170104 was carried out using strain data from LIGO (Laser Interferometer Gravitational Wave Observatory). The analysis presented is consistent with the published results on the subject. It was found that both systems produced gravitational waves from a pair of inspiraling black holes that approached very closely before merging. Different properties of the systems like chirp mass, compactness ratio, luminosity distance, eccentricity, redshift, and spin parameter were studied and the nature of the system was identified from the results.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"79 4","pages":"573 - 581"},"PeriodicalIF":1.3,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variability of the Ultraluminous X-ray Source M 74 X-1 in X-ray and Optical Ranges","authors":"A. S. Vinokurov,&nbsp;K. E. Atapin,&nbsp;Yu. N. Solovyeva,&nbsp;A. N. Sarkisyan","doi":"10.1134/S1990341324600753","DOIUrl":"10.1134/S1990341324600753","url":null,"abstract":"<p>Using observations of M 74 X-1 obtained with the Chandra X-ray Observatory and the Hubble Space Telescope, we identified this source in the optical range. Analysis of other archival data allowed us to track the evolution of M 74 X-1 over two decades of observations, as well as to search for a correlation between the object’s variability in the X-ray and optical ranges based on several available quasi-simultaneous observations. As a result, we revealed an approximately linear decrease in the object’s brightness of about <span>(1overset{textrm{m}}{.}9)</span> in the <span>(V)</span> band in the 2005–2021 time range, which is atypical for most ultra-luminous X-ray sources, and, presumably, is not caused by a change in the X-ray luminosity of the object. At the same time, we found changes in the nature of the short-term X-ray variability of M 74 X-1: by 2021, the stochastic variability of the object decreased and the quasi-periodic oscillations on a timescale of about 1.5 hours seen in observations of 2001–2002 disappeared.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"79 4","pages":"582 - 593"},"PeriodicalIF":1.3,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radio and Optical Properties of the Blazar PKS 1614(+)051 at (z=3.21)","authors":"Yu. V. Sotnikova,&nbsp;A. G. Mikhailov,&nbsp;A. E. Volvach,&nbsp;D. O. Kudryavtsev,&nbsp;T. V. Mufakharov,&nbsp;V. V. Vlasyuk,&nbsp;M. L. Khabibullina,&nbsp;A. A. Kudryashova,&nbsp;M. G. Mingaliev,&nbsp;A. K. Erkenov,&nbsp;Yu. A. Kovalev,&nbsp;Y. Y. Kovalev,&nbsp;M. A. Kharinov,&nbsp;T. A. Semenova,&nbsp;R. Yu. Udovitskiy,&nbsp;N. N. Bursov,&nbsp;S. A. Trushkin,&nbsp;O. I. Spiridonova,&nbsp;A. V. Popkov,&nbsp;P. G. Tsybulev,&nbsp;L. N. Volvach,&nbsp;N. A. Nizhelsky,&nbsp;G. V. Zhekanis,&nbsp;K. V. Iuzhanina","doi":"10.1134/S199034132460087X","DOIUrl":"10.1134/S199034132460087X","url":null,"abstract":"<p>We present a study of the radio and optical properties of the high-frequency peaker (HFP) blazar PKS 1614<span>(+)</span>051 at <span>(z=3.21)</span> based on the data covering the time period of 1997–2024. The radio data are represented by the instantaneous 1–22 GHz measurements from the SAO RAS RATAN-600 radio telescope, the 5 and 8 GHz data from the IAA RAS RT-32 telescopes, and the 37 GHz data from the RT-22 telescope of CrAO RAS. The optical measurements in the <span>(R)</span> band were collected with the SAO RAS 1-m Zeiss-1000 and 0.5-m AS-500/2 telescopes, and the ZTF archive data. We have found low overall variability indices (0.1–0.2) and a median spectral peak at 4.6 GHz, which is stable during the long-term period of monitoring. An analysis of the radio light curves reveals significant time delays (0.6 to 6.4 yrs) between the radio frequencies along with variability timescales ranging from 0.2 to 1.8 yrs in the source’s rest frame, which is similar to the blazars at lower redshifts. Spectral modeling suggests the presence of both synchrotron self-absorption (SSA) and free-free absorption (FFA) processes. Based on the SSA model, we provide estimates of the magnetic field strength which peaks at approximately 100 mG. A spectroscopic study with the BTA SCORPIO-1 spectrograph has found evidence of the regular motion of a neutral hydrogen envelope around the blazar center, which confirms the presence of a sufficient amount of gaseous matter to form an external FFA screen. The results highlight the importance of multi-wavelength and long-term monitoring to understand the physical mechanisms driving the variability in high-redshift blazars.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"79 4","pages":"548 - 572"},"PeriodicalIF":1.3,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Results of Magnetic Field Measurements with the 6-m BTA Telescope X. Observations in 2016","authors":"I. I. Romanyuk,&nbsp;A. V. Moiseeva,&nbsp;I. A. Yakunin,&nbsp;D. O. Kudryavtsev","doi":"10.1134/S1990341324600728","DOIUrl":"10.1134/S1990341324600728","url":null,"abstract":"<p>We continue the annual publications of the magnetic field measurements of chemically peculiar stars. Observations were carried out with the Main Stellar Spectrograph of the 6-m telescope at SAO RAS in 2016. We obtained 108 pairs of circularly polarized spectra for 64 stars. For five objects (HD 9050, HD 31592, HD 82093, HD 142502, and HD 190068), a magnetic field was discovered for the first time. We estimated the physical parameters (effective temperature <span>(T_{textrm{eff}})</span>, surface gravity <span>(log g)</span>, projected rotation velocity <span>(v_{e}sin i)</span>) and the radial velocity <span>(V_{r})</span> for all the objects.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"79 4","pages":"644 - 663"},"PeriodicalIF":1.3,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Instabilities of the Kinematic State of the Atmospheres of Single C-Rich Post-AGB Stars","authors":"V. G. Klochkova,&nbsp;V. E. Panchuk,&nbsp;N. S. Tavolzhanskaya,&nbsp;M. V. Yushkin","doi":"10.1134/S1990341324600959","DOIUrl":"10.1134/S1990341324600959","url":null,"abstract":"<p>To search for and study the instabilities in the atmospheres of selected post-AGB stars, we have performed a long-term high-resolution spectroscopy (<span>(Rgeq 60,000)</span>) with the NES spectrograph of the 6-m BTA telescope. Low-amplitude pulsations, splitting and/or asymmetry of the absorption profiles with a low excitation potential (mainly absorptions of <span>(s)</span>-process metals), as well as variability of a complex <span>(H_{alpha})</span> profile have been registered in the optical spectra of single stars associated with the IR sources IRASz02229+6208, IRAS 04296+3429, IRAS 07134+1005, IRAS 07430+1115, IRAS 19500<span>(-)</span>1709, IRAS 22223+4327, and IRAS 23304+6147 that had previously undergone the third mixing. The maximum pulsation amplitude <span>(A_{V_{r}})</span> was detected for the stars in the IRAS 07134+1005 and IRAS 19500<span>(-)</span>1709 systems, which have the maximum temperatures among the stars in the studied sample. Stratification of radial velocity in the atmosphere was found for two stars in the sample. The luminosity of the studied stars was estimated based on the intensity of the IR oxygen triplet O I <span>(lambda)</span> 7774. Moreover, a luminosity of <span>(log L/L_{odot}approx 3.1)</span> was obtained for the star in the IRAS 07430+1115 system within the range of typical post-AGB star luminosity values, which eliminates the paradox of the luminosity and the initial mass of this object.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"79 4","pages":"614 - 628"},"PeriodicalIF":1.3,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in the Structure of the Sun’s Activity Belts from Flares to Nanoflares","authors":"A. S. Kirichenko,&nbsp;A. A. Reva,&nbsp;S. A. Bogachev,&nbsp;I. P. Loboda","doi":"10.1134/S1990341324600741","DOIUrl":"10.1134/S1990341324600741","url":null,"abstract":"<p>Based on data from the ‘‘TESIS’’ scientific instrumentation aboard the ‘‘CORONAS–Photon’’ satellite, collected during the solar activity minimum of 2009, the positions on the disk of 1014 solar flares were analyzed, with X-ray classes ranging from A0.003 to C2.7. A change in the spatial distribution was found in the region of class A events. As flare power decreases, a transition is observed from their localization within the activity belts to a more uniform latitudinal distribution. An estimate of the asymmetry in the positioning of the events on the solar disk was also obtained—0.009. Thus, it was established that the number of flares in the southern and northern hemispheres is almost identical.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"79 4","pages":"674 - 682"},"PeriodicalIF":1.3,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectroscopic Binary Cepheid V350 Sgr: Revision of Physical Characteristics and Evolutionary Status","authors":"A. S. Rastorguev,&nbsp;M. V. Zabolotskikh,&nbsp;N. A. Gorynya","doi":"10.1134/S1990341324600625","DOIUrl":"10.1134/S1990341324600625","url":null,"abstract":"<p>Based on the original version of the pulsating photosphere method that allows modeling the changes in the effective temperature, a revision of the physical characteristics of the unique binary Cepheid V350 Sgr was carried out. Previously published measurements of radial velocities were used, as well as new ones obtained by us, which allowed us to refine the parameters of the Cepheid orbit. The choice of the projection factor <span>(PF=1.34)</span> allowed us to reconcile our estimates of the cycle-averaged radius <span>(langle{R}rangle_{I}/R_{odot}approx 41.3{-}41.9)</span>, luminosity <span>(M_{V}approx-3overset{textrm{m}}{.}52{-}3overset{textrm{m}}{.}57)</span>, normal color <span>((B-V)_{0}approx 0overset{textrm{m}}{.}56pm 0overset{textrm{m}}{.}01)</span>, effective temperature <span>(langlelog{}T_{textrm{eff}}rangle_{I}approx 3.788pm 0.002)</span>, distance <span>(Dapprox 992pm 14)</span> pc and color excess <span>(E(B-V)approx 0overset{textrm{m}}{.}35pm 0overset{textrm{m}}{.}01)</span> with <span>MESA</span> theoretical evolutionary tracks for the mass <span>(5.1M_{odot})</span> and metallicity <span>([{textrm{Fe}}/{textrm{H}}]=-0.18)</span> dex (or mass <span>(5.2M_{odot})</span>, <span>([{textrm{Fe}}/{textrm{H}}]approx-0.10)</span> dex) and the <span>PARSEC 2.0</span> track for the mass <span>(5.2M_{odot})</span>, <span>(Zapprox 0.01)</span>. The evolutionary age of the Cepheid, which is in the phase of the third crossing of the instability strip, is estimated at 100 Myr. It is shown that the Gaia eDR3/DR3 catalogues provide a distance overestimated by approximately 25%. Using the mass function for the available estimates of the Cepheid and companion masses, the relative orbital plane inclination angle <span>(iapprox 53^{circ}pm 3^{circ})</span> and the orbital semi-major axes <span>(a_{1}approx 1.63pm 0.05)</span> AU, <span>(a_{2}approx 3.42pm 0.09)</span> AU were determined for the first time, with the relative orbit size of about 5 AU.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"79 4","pages":"629 - 643"},"PeriodicalIF":1.3,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Parameters of Approaches to the Earth by Asteroids","authors":"R. V. Zolotarev,&nbsp;B. M. Shustov","doi":"10.1134/S1990341324600947","DOIUrl":"10.1134/S1990341324600947","url":null,"abstract":"<p>The paper presents the results of statistical modeling of the entry of near-Earth asteroids (NEAs) into near-Earth space (NES)—a sphere with a radius of 0.01 AU around the Earth. Distributions of asteroids by direction and velocity of entry into NES are constructed. The NEA population was modeled using the <span>NEOMOD</span> software with subsequent integration of the dynamic evolution for 110 years using the <span>REBOUND</span> package. It is shown that: 1) the number of asteroids larger than 10 m entering NES is approximately 1000 per year; 2) up to half of the asteroids can enter NES from the dayside hemisphere; 3) the asteroid flux density is increased in the solar and antisolar directions. Typical velocities of approach to the Earth when entering the NES are approximately 7.5 km s<span>({}^{-1})</span> (the velocities range is from 0 to 30 km s<span>({}^{-1})</span>). The distribution of entries by distance and velocity relative to an observer located at the Lagrange point <span>(L_{1})</span> of the Sun–Earth system is also calculated. These distributions can be useful in designing the System of Observation of Daytime Asteroids (SODA).</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"79 4","pages":"683 - 691"},"PeriodicalIF":1.3,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}